Like wine, sushi, and plumbers, headphones can get a lot more expensive than most people realize. At Sound+Vision, we focus on under-$500 models. But when Dr. Fang Bian, the visionary entrepreneur behind the HiFiMan headphone company, asked if I’d like to try the company’s top-of-the-line, $1,299 HE-6 headphone and its new $1,599 EF-6 headphone amplifier, I thought it’d be a great chance to give our usual listening panel a sample of what only the most devoted and/or wealthy headphone aficionados usually get to hear.